Storage of inflammable liquids



March 4 1924. 1,485,518

J. MUCHKA STORAGE OF INFLAMMABLE LIQUIDS Filed Jan. 6. 1921 2 Sheets-Sheet 1 MmhA 1924. 1,485,518

J. MUCHKA STORAGE OF INFLAMMABLE LIQUIDS Filed Jim-1 46. L921 2 Sheets-Sheet 2 Inventor 17TH mid dtbys.

ldatented Mar. 4, 1924.

:ATENT" JOSEF MUGHKA, or VIENNA, AUSTRIA.

STORAGE OF INFLAMM-ABLE LIQUIDS.

Application filed January 6, i921. steam. 435,551.

1') storage vessel and for tapping off these liq uids from the storagevessel in which the liquid is stored under a non-explosive gas mixture saturated with liquid vapours, a pump being used for transferring the liquid, suffer from the drawback that the external air may How in through leaky or defective places in the fittings and in the storage vessel during the pumping, and owing tothe consequent dilution of the protective gas filling of the storage vessel, explosive mixtures of air and vapour may be formed, thereby increasing the danger of explosion.

The object of this invention is to prevent the formation of such explosive mixtures of air and vapour.

It has previously been proposed to use air to form the protective gas filling of the storage vessel and to effect the saturation of the off is dependent on the partial vacuum or low pressure created in the storage vessel in such a manner that it falls off and ceases when the vacuum falls off and is broken.

For carrying out this method, an appara- 45 tus is employed which on the one hand comprises a saturating vessel which is in com- .iunication with the storage vessel, the said saturating vessel containing a liquid for sat-- urating the air and being provided with an air inlet pipe which is isolated from the storage vessel by the liquid contained in it as has previously been-proposed, and on the other hand includes a liquid conveying pump, the

suction side of which is connected to the gas space of the storage vessel by means of a by pass which does not take part in the convey- 111 efthe liquid and which i adapted to be shut o-fl" at a certain degree o'fyacuum.

' Two constructio al forms of an ap aratus for carrying out the method according to this invention are, illustrated by way of example in Figs. '1 and '2 of the accom anying drawings a c I the onstructional fermshown in Fig. 1 the apparatu includes a storage vessel 1 for the 1iqu id,'whieh'is stored underground, and a pump-2 which is shown as a rotary pump for conveying the liquid. The suction pipe 13 of the pump is connected by means of; a pressure equalizing i pipe 14: which branches off from it to the gas space of the storage vessel 1. In this pressure equalizing pipe 14 is interposed a vacuumivalve 3 which causes the communication between the pump suction pipe 13 and the gas space of the storage vessel to be interrupted-when the vacuum in the storage vessel reaches acertaindegree. The valve 3 comprises a valve disc 31 and a diaphragm 32 which a e eenneetedtogether by a valve stem, 33. 7 One side of: thediaphragm is acted on by a spring 34; which presses on the diaphragm upwardly, tending to keep the valve disc raised from its seating, while the other side'of the diaphragm is under atmospheric pressure. In the normal position the valve disc is in the open position so that the suction pipe 13 communicates with the storage vessel 1 through the intermedia'ry of the pipe 14. When the pump 2 is put into operation, a partial vacuum or low pressure is produced in the storage vessel 1 owing to the storage vessel being The pressure efthe outside air on the outside surface of the diaphragm is greater than the pressure which acts on the inside surface of the diaphragm which is conse-- quently forced downwardly. This movement of the diaphragm causes the valve disc ,in communication with the'suc'tio'n pipe 13.

to be forced down on to its seating and the pump is incapable of delivering liquid from the storage vessel. The delivery pipe 15 of the pump is connected by means of a pipe 4 with an apparatus for forming a saturated mixture of air and vapours generated from the liquid contained in the vessel 1. This apparatus consists of a saturating vessel 5 arranged in the storage vessel 1 and communicating with the space thereof which does not contain liquid, the pump being adapted to deliver liquid to. the said saturating vessel, and of an air pipe 6 which passes down into the vessel 5 to within a short distance of the bottom, through which pipe air is drawn into the vessel 5 as soon as a vacuum is created in the storage vessel 1 owing to the suction action of the pump 2. The pipe 4: is connected to the vessel 5 through the medium of a vessel 7 which is interposed in the air pipe 6. The pipe 6 has at its lower end a number of small openings 8 through which the air drawn through the pipe 6 can bubble up into the saturator 5. The storage vessel 1 is fittedwith a filling pipe 10 which is adapted to be closed airtight by means of a closure 12. A trap 9 and means for preventing diffusion are interposed in the suction pipe 13 of the pump and safety devices consisting of nests of tubes 11 are interposed in the pipes 1, 6 and 14:.

The constructional form shown in Fig. 2 differs from that of Fig. 1 by the saturating vessel 5 for forming the saturated mixture of air and liquid vapors being arranged separate from the storage vessel 1 and being made to receive an auxiliary liquid which gives off lighter vapours than the liquid contained in the vessel 1. The auxiliary liquid is delivered to the vessel 5 by means of a pipe 18 which is provided with a heating coil 17 for the purpose of heating the liquid. 1

The mode of operation of the apparatus shown in Fig. 1 is as follows:-

When the storage vessel 1 is to be filled with liquid from a drum, the closure 12 of the filling pipe 10 is first opened and the drum,,not shown, is connected up to the open filling pipe by means of a connectingtube. The pump2 is then put into operation. By means of the suction action of the pump a vacuum is created in the filling pipe 10 which causes the liquid to be sucked out of the drum situated at a higher level into the trap 9 from which it falls through the suction pipe 13 of the pump by its own weight into the storage vessel 1. The air imprisoned in the storage vessel 1 is displaced and forced by the liquid into the vessel 5 which has been previously filled with liquid which gives 0% vapours readily and which may be the same liquid as that which is to be storedunder protective gas in the storage vessel 1. In consequence of the pressure generated in the storage vessel 1 by the displacement of the air, the liquid contained in the vessel 5 will be forced into the vessel 7 whereby the openings 8 will be uncovered and the air displaced out of the storage vessel will be able to pass out through the pipe 6. When the pressure in the storage vessel 1 falls, as it does when the supply of liquid has terminated, then the liquid falls back from the vessel 7 into the vessel 5.

At the end of the filling operation the filling pipe 10 is closed airtight by means of the closure 12.

If liquid is to be tapped of? from the stor' age vessel 1, the pump 2 is put into action. A vacuum is formed in the vessel 1 by means of the suction action of the pump whereby the vacuum valve 3 immediately comes into operation and shuts OK the pipe 14 from the storage vessel 1 so that the pump 2 only communicates with the storage vessel by means of the suction pipe 13. This vacuum on the one hand causes vaporization of the liquid in the vessel 1 and on the other hand causes air to be drawn through the pipe 6 and through the openings 8 into the saturating vessel 5 and from this into the vessel 1 by an amount equivalent to that of the liquid re moved. The column of liquid standing in the saturating vessel 5 sets up a resistance to the incoming air of such magnitude that the vacuum in the vessel 1 will not be broken while at the same time the saturation and mixing of the sucked in air with liquid vapours is sustained by the air sweeping through this column of liquid. The degree of vacuum which operates the vaporization and the saturation of the air is governed by the height of the column of liquid above the openings 8, this height being dependent on the vaporization temperature of the liquid present in the vessel 5. During the tapping operation the pump 2 delivers a portion of the liquid raised by it through the pipe 1 over the vessel 7 into the saturating vessel 5, so that the height of liquid therein and thereby the necessary liquid resistance to maintain the vacuum in the vessel 1 can be kept constant. 7

If the tapping is discontinued by stopping the pump 2, then the vacuum in the vessel 1 is destroyed automatically by the vaporization of the liquid in the storage vessel and the vacuum valve 3 is opened automatically thereby reestablishing communication between the suction pipe 13 and the pressure equalizing pipe 14: connected up to it. The suction pipe of the pump will therefore be emptied automatically when the tapping is discontinued.

If the vessel 1 or one of the pipes is leaking then the pump 2 is unable to create a vacuum. If in consequence of a leak in the vessel 1 or in the pi es or owing to want of the column of liquid in the saturating vesthe latter vessel.

tured then the pump 2 can only convey liquid out of the storage vessel 1 as long as a column of liquid suflicient to maintain the vacuum is present in thevessel 5. It the column of liquid is exhausted then the vacuum in the vessel 1 cannot be maintained.

The pump 2 therefore ceases to deliver when the formation of a saturated mixture oi air and vapour 1s no longer possible.

Consequently a vacuum can only be pro-' duced in the storage vessel by the action of the pump 2 when the filling pipe 10 is closed in an airtight manner and the vessel'l, the suction pipe 13, and the pipe 14 do not leak at any point; rurther when the liquid in the vessel 5 is at the height required to maintain the vacuum and the vacuum valve 3 is closed by the pressure of the air outside owing to the vacuum formed in the vessel 1.

In the constructional form shown in Fig. '2, the air which is displaced out of the storage vessel 1 during the filling thereof is forced into the saturating vessel 5 from which it can pass out through the air pipe 6.

In this form of construction the mode of operation is the same as that in the previously described example. If the liquid in the vessel 1 only vaporizes with difiiculty the mixture of air saturated with liquid vapours is formed by means of a readily vaporized liquid, for instance petrol, which is passed into the vessel 5. The vacuum created in the vessel 1 by the suction action of the pump 2, owing to the vessels 1 and 5 being in communication is also formed in The vaporization of the auxiliary liquid is assisted by suitable preheating the supply-pipe 18 by means of a heating coil 17.

Having now described my invention what I claim as new and desire to secure by Letters Patent is 1. Apparatus for storing and tapping oif liquids from storage vessels in which the liquid is stored, under a mixture of gas saturated with liquid vapours, comprising in combination a storage vessel, an air inlet pipe leading in an auxiliary vessel communicating with the gas space of the storage vessel and containing a liquid for shutting off the air inlet pipe from the storage vessel, a suction pump for drawing off the liquid from the storage vessel and for creating a partial vacuum in the storage vessel and for drawing in air in the auxiliary vessel and means for preventing the pump from drawing liquid when the partial vacuum V tall'sotl and is broken. H

Apparatus for storing and tapping oil liquids from storage vessels in which the liquid is stored under a 'miXture of gas saturated with liquid vapours, comprising in combination a storage vessel, a saturating vessel communicating with the storage .vessel and containing a liquid 'for saturating the gas, an air inlet pipe provided on the said saturating vessel, the said air inlet pipe being shut ofif from the storage vessel by the liquid contained in the saturating vessel, a suction pump for drawing on the liquid and for creating a partial vacuum in the storage vessel, a bypass connecting the suction side of the said pump with the gas space of the storage vessel and means arranged in the bypass for preventing the pump from drawing when the said partialvacuum falls off and is broken.

3. Apparatus for storing and tapping off liquids from storage vessels in which the liquid is stored under a mixtureof gas saturated with liquid vapours, comprising in combination a storage vessel, a saturating vessel communicating with the storage vessel and containing a liquid for saturating the gas, an air inlet pipe provided on the said saturating vessel, the said air inlet pipe being shut off from the storage vessel by the liquid contained in the saturating vessel, a suction pump for drawing oil the liquid and for creating a partial vacuum in the storage vessel, a by-pass connecting the suction side of the said pump with the gas space or the storage vessel, the said by-pass comprising a pressure equalizing pipe and an automatic vacuum valve for isolating the pressure equalizing pipe from the suction side of the pump.

1. Apparatus for storing and tapping oif liquids from storage vessels in which the liquid is stored under a mixture of gas saturated with liquid' vapours, comprising in combination a' storage vessel, a saturating vessel communicating with the storage vessel and containing a liquid for saturating the gas, an air inlet pipe provided on the livery side of the pump and the-saturating I vessel.

5. Apparatus for storing and tapping off liqulds from storage vessels in which the liquid is stored under a mixture of gas saturated With liquid vapours, comprising in combination a storage vessel, means for saturating the gas With an auxiliary liquid to the saturating vessel, a pipe supplying auxiliary liquid to the saturating vessel, a suction pump for, drawing off the liquid, and for creating a partial vacuum in the storage vessel and means for preventing the pump from drawing when the said partial vacuum 10 falls OE and is broken.

In testimony whereof I have signed my name to this specification.

J OSEF MUCHKA. 

